[llvm] [InstCombine] Preserve nuw/exact flags when transforming (C shift (A add nuw C1)) --> ((C shift C1) shift A). (PR #79490)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

Generalized proofs: https://alive2.llvm.org/ce/z/mB-rWz

Note that you can preserve nsw as well.

https://github.com/llvm/llvm-project/pull/79490